LPS immunoblot using an anti-A. actinomycetemcomitans antibody. A total of 500 ng of phenol-water-purified LPS was resolved on 4 to 15% polyacrylamide Tris-HCl Ready Gels. The separated carbohydrate molecules were transferred to a nitrocellulose membrane and probed with purified rabbit anti-A. actinomycetemcomitans immunoglobulins. WT, wild type (VT1169); rmlC, rhamnose epimerase mutant; rmlC/rlmC+, rhamnose epimerase complemented; waaL, O-antigen ligase mutant; waaL/waaL+, O-antigen ligase complemented; wzt, ATP-binding cassette sugar transport mutant.